I suppose it depends on what boats you are comparing with. If your buddies have lower volume kayaks that might well be the reason – in fact I find the NH almost too wide/large although it really is a fun and fast boat to ride.
The NH is a relatively hard-chined boat which is good for initial stability and leaning (for steering) but it comes at the price you described.
Another reason is probably the weight of your boat which is likely a lot lighter than the glass fiber ones. Because it is so light it tends to be more "nervous" on the water – but that in turn gives you higher speed and better control.
Adding weight to the bow is not a good idea. If you are keen, add weight throughout the hull – but I wouldn't want that, either.
Try playing with the position of your seat, 2" forward can make a big difference.

Best, Matt